Formatting output of R dataframe - r

Question

So i currently have a dataframe in R and I want to export/write it to a text file using write.table()
Here's an example of the dataframe:
ID FirstName LastName Class
1000 John NA C-02
1001 Jane Wellington C-03
1002 Kate NA C-04
1003 Adam West C-05
I want to write it to a text file where for each row, if any column value is NA, then it won't include the word "NA" but proceed to the other column. The output I want:
1000 John C-02
1001 Jane Wellington C-03
1002 Kate C-04
1003 Adam West C-05
Example as shown, the first row didn't have a last name entered, so I will proceed to the next column, preventing something like:
1000 John NA C-02
I did the write.table() command:
write.table(df, "student_list.txt", col.names = FALSE, row.names = FALSE, quote = FALSE, sep="\t")
But the problem is I'm getting the one where NA is included in the second output i mentioned.

Answer 1

library(tidyverse)
dta <- tribble(
~ID, ~FirstName, ~LastName, ~Class,
1000, "John", NA, "C-02",
1001, "Jane", "Wellington", "C-03",
1002, "Kate", NA, "C-04",
1003, "Adam", "West", "C-05"
)
dta %>%
unite(column, everything(), sep = " ") %>%
mutate(column = str_remove_all(column, "NA ")) %>%
write.table("student_list.txt", col.names = FALSE, row.names = FALSE, quote = FALSE, sep = "\t")

Answer 2

I would use apply to remove the NAs and convert rows into text lines (using paste), as follows:
data <- apply(df, 1, function(row){
paste(row[!is.na(row)], collapse="\t")
})
write.table(data, "student_list.txt", col.names = FALSE, row.names = FALSE, quote = FALSE, sep="\t")
File output would look like the following:
#1000 John C-02
#1001 Jane Wellington C-03
#1002 Kate C-04
#1003 Adam West C-05